Orthopedic Surgery Notes

Anesthesia for Orthopedic Surgery

Speaker: Elisha Coppens, DNAP, Mpharm, CRNA, APRN, CHSE, COI

Objectives

  • Discussion Points:

    • Types of patients who have orthopedic surgery

    • Related diseases and conditions

    • Types of surgeries with a focus on the most common

    • Complications associated with each surgery type

    • Anesthesia techniques and positioning

    • Specific equipment, monitors, and drugs used in orthopedic surgeries

Overview of Orthopedic Surgery

  • Orthopedic surgery is performed on patients with:

    • An acquired injury

    • A disease process

    • A congenital abnormality

  • Patient Demographics:

    • Young: ASA I, typically presenting with a fracture

    • Middle-Aged: ASA II or III, often for total joint replacement

    • Elderly: ASA III or IV, commonly for stabilization of a fracture

Osteoarthritis (OA)

  • Description:

    • A degenerative disease affecting the surface of one or more joints, mainly the hip and knee.

  • Causative Factors:

    • Repetitive joint trauma

    • Obesity: Contributes to joint destruction

  • Implications for Anesthesia:

    • Osteoarthritic changes complicate patient positioning, making laryngoscopy and intubation challenging, as well as positioning for regional techniques.

Ankylosing Spondylitis (AS)

  • Characteristics:

    • Familial disorder linked with the histocompatibility antigen HLA-B27.

    • Presents as low back pain in young men with gradual onset.

    • Progresses to increased restriction of spinal movement with hip and shoulder arthritis.

    • The spine exhibits a bamboo-like appearance.

  • Anesthetic Considerations:

    • Fix flexion deformity is necessary.

    • Regional anesthesia may present challenges due to abnormal spread of local anesthetics.

    • Proper padding critical for positioning difficulties.

    • Advanced cases show reduced lung volumes.

Muscular Dystrophies

  • Definition:

    • Painless degeneration and atrophy of skeletal muscle leading to various complications.

  • Complications:

    • Patients exhibit kyphoscoliosis and flexion contractures.

    • Respiratory issues due to muscle degeneration leading to ineffective coughing and pulmonary infections.

    • EKG Changes:

    • Prolonged PR interval, QRS and ST abnormalities, prominent R waves on right, deep Q waves on left.

  • Mortality:

    • Death primarily results from recurrent pulmonary infections, respiratory failure, and cardiac failure, with reduced life expectancy (often by ages 15-25).

Duchenne’s Muscular Dystrophy

  • Characteristics:

    • Most common and severe type of muscular dystrophy, inherited as an X-linked recessive disorder, affecting only males.

    • Associated with fatty infiltration of muscles, including respiratory and cardiac muscles.

    • Leads to progressive weakness and contractures, typically causing kyphoscoliosis.

    • Early death often occurs due to cardiac or respiratory causes.

  • Anesthetic Considerations:

    • Avoid preoperative medications due to increased aspiration risk.

    • Complex positioning for surgery; succinylcholine is contraindicated due to the risk of malignant hyperthermia (MH) or severe hyperkalemia.

    • Non-depolarizing muscle relaxants may be used with caution; muscle wasting complicates reversal.

    • Patients are generally considered to have a full stomach due to decreased GI motility.

    • Volatile anesthetics may cause significant respiratory and circulatory depression.

    • Regional or local anesthetics can be utilized with positioning challenges.

    • Intubation difficulties anticipated due to kyphoscoliosis and neck contractures, often necessitating temporary ventilation.

Tourniquets

  • Function and Considerations:

    • Tourniquets facilitate a bloodless surgical field but can induce significant physiological changes and risks for patient injury.

    • Proper sizing is critical; the cuff should overlap to prevent gaps and adequately protect the skin with under-padding.

  • Usage Procedure:

    • Extremity must be exsanguinated prior to inflation through either elevation or an Esmarch bandage.

    • Recommended inflation pressure: approximately 100 mmHg over SBP, with maximum pressures:

    • Upper extremities: 250 mmHg

    • Lower extremities: 300 mmHg

    • Record tourniquet times and pressure; maximum time should not exceed 2 hours to prevent tissue damage.

  • Pain and Response to Inflation:

    • Tourniquet pain may develop 45-60 minutes post-inflation, similar to thrombotic vessel occlusion pain, and requires additional narcotic analgesia beyond standard anesthesia.

  • Consequences of Release:

    • Following release, patients experience transient metabolic acidosis, decreased arterial pressure, increased ETCO2, and a potential rare incidence of pulmonary embolism post knee surgery.

Types of Orthopedic Surgery

  • Categories:

    • Spine and Neck

    • Upper Extremities and Hands

    • Shoulder

    • Pelvis

    • Hip

    • Knee

    • Foot and Ankle

Antibiotic Prophylaxis

  • Administration:

    • All orthopedic patients receive an antibiotic prior to surgery, regardless of whether the procedure is elective or emergent.

    • Important for preventing infections such as osteomyelitis, which is notoriously hard to treat.

Tranexamic Acid (TXA)

  • Description:

    • Synthetic plasminogen activator that decreases blood loss by inhibiting fibrinolysis and clot degradation.

    • Commonly used in total joint arthroplasties or fractures/repairs of long bones.

  • Dosing:

    • Administer 1-2 g during perioperative period, with maximum limits to not exceed 2 g.

    • Can be given IV or topically on the surgical field, at any stage during surgery.

Upper Extremity Surgery

  • Procedures:

    • Treatments often performed for conditions like arthritis, tendon and nerve injuries, or fractures.

    • Positioning typically requires the patient to be supine while the table is rotated 90 degrees away from the operative side, with NIBP cuff and peripheral IV on the non-operative side.

Hand Surgery

  • Common Procedures:

    • Includes carpal tunnel release (most common elective surgery), Dupytren’s contracture release, finger joint arthroplasties, and traumatic injury repairs.

  • Anesthetic Techniques:

    • Various techniques based on procedure type:

    • Bier Block

    • Axillary Block

    • Brachial Plexus Block

    • General Anesthesia

    • Local Anesthesia with Sedation

Arm Surgery

  • Examples:

    • Radius/Ulna fracture repair

    • Humerus fracture repair

    • Elbow surgery (open or arthroscopic).

  • Anesthesia Options:

    • Generally involves the use of a tourniquet (except for humerus).

    • Regional techniques may provide effective postoperative pain relief.

Shoulder Surgery

  • Types:

    • Can be performed either open or arthroscopic.

  • Positioning:

    • Can be in either lateral or 'beach chair' positions, with careful attention to securing the head, neck, and hips, and ensuring avoidance of excessive neck rotation to prevent brachial plexus injury.

Anesthesia for Shoulder Surgery

  • Techniques:

    • Patients may be awake and sedated with an interscalene block or undergo general anesthesia with TIVA or volatile agents, determined by patient history, size, and comorbidities.

Hip Fracture

  • Urgency:

    • Emergent surgery often performed on elderly patients with multiple comorbidities.

    • Potential complications include dehydration, confusion, frailty, and preoperative hypoxia.

  • Mortality Rate:

    • Approximately 10% mortality during the initial hospitalization period.

Types of Hip Fractures

  • Common Types:

    • Intracapsular (femoral neck) fracture

    • Intertrochanteric fracture

    • Subtrochanteric fracture

    • Hemiarthroplasty

    • Internal fixation

    • Hip compression screw

    • Total hip replacement

Hip Fracture Positioning and Anesthesia Implications

  • Positioning:

    • Based on fracture type, may be supine or lateral.

  • Anesthesia Implications:

    • General or regional anesthesia options with considerations for lung function and thromboembolic reduction.

    • Postoperatively, regional techniques may lower mortality due to decreased thromboembolic risks within the early postoperative phase.

  • Considerations for Anticoagulation:

    • Must consider timing when using regional anesthesia, especially regarding heparin and neuraxial anesthesia.

Total Hip Replacement (THR)

  • Description: - Elective surgical procedure typically performed with patients in lateral positions. Common issues include bone cement implantation syndrome, intra- and postoperative hemorrhage, and venous thromboembolism.

  • Monitoring Requirements:

    • Two large bore IVs, +/- arterial line, EKG monitoring, ETCO2 measurement, SaO2 levels, and temperature monitoring.

  • DVT Prophylaxis:

    • Compression stockings, boots, and possible administration of heparin SC or LMWH.

Total Knee Replacement (TKR)

  • Patient Profile: - Similar to those undergoing total hip replacement; typically less blood loss due to tourniquet use.

  • Anesthesia Considerations: - Combination of neuraxial anesthesia and regional block is possible; DVT prophylaxis is essential.

Trauma Considerations

  • Fractures:

    • Long bone fractures can be life-threatening due to vascular injuries; significant hemorrhage is a potential complication.

    • Fat embolism may occur 1-3 days post-injury.

    • Emphasize fluid resuscitation and warming measures.

Complications in Orthopedic Surgery

  • Common Complications:

    • Fat Embolism

    • Pulmonary Embolism

    • Deep Vein Thrombosis (DVT)

    • Interaction with cement

    • Compartment Syndrome

    • Positioning injuries

Fat Embolism

  • Overview:

    • Typically occurs within 72 hours after hip fractures; originates primarily from long bones and pelvic regions.

  • Signs:

    • Confusion, dyspnea, petechiae.

    • Clinical signs under anesthesia include decreased ETCO2, arterial O2 saturation < 60 mmHg, and right-sided heart strain.

Fat Embolism Syndrome (FES)

  • Clinical Presentation:

    • Cardiovascular: persistent tachycardia, hypotension

    • Respiratory: dyspnea, hypoxia, hemoptysis, and fat globules in sputum.

    • Neurological: delirium, stupor, seizure, and coma.

    • Cutaneous: petechiae

    • Other Symptoms: jaundice, fever, urinary fat globules, hyperthermia, and lab findings such as decreased platelets and increased sedimentation rate.

Treatment of FES

  • Prophylaxis:

    • Early fracture stabilization.

  • Supportive Care:

    • Enhanced respiratory care.

    • Monitoring volume status and potential inotropic needs.

    • High-dose corticosteroids as adjunct therapy.

DVT & Thromboembolism

  • Mechanisms:

    • Pathophysiology includes venous stasis, hypercoagulable state, and endothelial damage.

  • Risk Factors:

    • Obesity, age > 60, surgeries lasting > 30 mins, proximal lower extremity fractures, and prolonged immobilization.

  • Prevention:

    • Utilization of prophylactic anticoagulants such as low-dose heparin, warfarin, low molecular weight heparin, as well as mechanical compression methods.

Pulmonary Embolism

  • Definition:

    • The entry of various material (e.g., blood clots, fat, tumor cells) into the venous system, most commonly arising from the lower extremities or the right side of the heart.

  • Clinical Signs:

    • Sudden onset tachypnea, dyspnea, chest pain, hemoptysis, unequal ABG findings.

  • Intraoperative Signs:

    • Hypotension, bronchospasm, hypoxemia, decreased ETCO2.

  • Prevention methods:

    • Use of anticoagulants, patient mobilization, and mechanical devices to enhance venous return.

Bone Cement in Surgery

  • Use:

    • Polymethylmethacrylate (MMA) is commonly used in joint replacements, but its exothermic reaction can induce medullary hypertension.

  • Bone Cement Implantation Syndrome:

    • Associated with the release of vasoactive substances leading to symptoms including hypotension, hypoxia, and cardiac rhythm abnormalities.

    • Management involves supportive care and vigilant monitoring perioperatively.

Compartment Syndrome

  • Description:

    • Condition where swelling or bleeding occurs within a muscle compartment, frequently seen in the arms and legs, often resulting from trauma or surgery.

  • Symptoms:

    • Severe pain, muscle tightness, and progression to numbness or paralysis indicating potential irreversible damage.

  • Management:

    • Requires immediate surgical intervention if pressures exceed 40 cm H2O post-measurement.

Anesthetic Considerations for Compartment Syndrome

  • Setting:

    • Should be treated as a surgical emergency, typically requiring general anesthesia and airway management under rapid sequence induction (RSI).

Conclusion

  • Final Notes:

    • These comprehensive aspects of orthopedic surgeries, anesthesia considerations, and potential complications are crucial for safe procedural outcomes.

References and Acknowledgments

  • Source of Information:

    • Presented material is based on current medical guidelines and knowledge in orthopedic anesthesia as understood from clinical texts and experience in the field

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